Fig. 2

Combined prediction model. a Kaplan–Meier curves of OS according to the following scoring system, with 1 point assigned to each independent prognostic factor (a low PNI [< 42], lymph node metastasis, and tumor differentiation [poor]) using similar odds ratios as those reported in the multivariate analysis. The total score in the combined prediction model was calculated as the sum of the scores assigned to each independent prognostic factor. Accordingly, patients were divided into four groups, according to the number of risk factors (0, 1, 2, and 3). The proportion of patients in each group who survived was significant (P < 0.001). b Receiver operating characteristic curves of the scoring system. Predictive power was compared using the AUC for each point in the scoring system. AUC area under the curve, OS overall survival, PNI prognostic nutritional index